The gel state of cured silicone rubber (which is abbreviated as silicone gel hereinafter) is excellent in electrically insulating property, stability of electric characteristics and pliability, so it is used for potting and sealing electric and electronic parts, especially coating control circuit elements, such as power transistor, IC, condenser and so on, to protect the parts against thermal and mechanical problems. However, for all the above-described characteristics, the prior art silicone gels do not cope satisfactorily with the recent trend of electronically controlling various devices installed in cars. Therefore, it has been desired to develop a silicone gel which additionally has resistance to hydrocarbon fluid and gasoline. Though the introduction of CF.sub.3 CH.sub.2 CH.sub.2 -group has been recommended as solvent resistance-imparting means, the silicone gel into which said group is introduced suffers from considerable deterioration in heat resistance in the open air and becomes rigid in a short time at high temperatures to lose its original characteristics. Accordingly, the above-described silicone gel is not suitable for car use. As a result of concentration of our energies on solution of the above-described problem, it has now been found that heat resistance of silicone gel can be remarkably enhanced by adding an aromatic amine-containing organopolysiloxane to a silicone gel composition, thus achieving this invention.